A Randomized Controlled Trial of Gabor-Based Perceptual Learning for Adult Amblyopia

This study is initiated and conducted by the Shanghai Eye Disease Prevention and Treatment Center / Shanghai Eye Hospital. Many people once believed that amblyopia (commonly known as "lazy eye") could only be treated during childhood (the critical period of visual development) and that nothing could be done once we reached adulthood. However, modern visual science research has revealed that the adult visual cortex still retains a certain degree of "neuroplasticity" (the brain's ability to reorganize, learn, and adapt). The Gabor target training used in this study-powered by RevitalVision software-is a scientifically proven visual training program. By repeatedly performing visual tasks near your perception threshold on a computer screen, this training exercises your eye-brain coordination, helping your brain process visual information much more efficiently.

To help you and your family participate with peace of mind, we have compiled the following answers to frequently asked questions:

Q1: How will I participate in this study? What is the difference between the two groups?

To scientifically compare the training's effectiveness, this study uses a rigorous randomized controlled design. A total of 80 eligible participants will be randomly assigned by a computer program in a 1:1 ratio to one of two groups:

Immediate Training Group:

You will begin the 12-week home-based Gabor visual training right after randomization. Your study participation ends after your Week 12 follow-up.

Delayed Training Group:

During the first 12 weeks after randomization, you will simply wear your prescribed glasses and go about your daily life without active visual training.

After completing your Week 12 eye evaluation, you will receive the exact same 12-week Gabor visual training for free (conducted from Week 12 to Week 24).

Please be assured: No matter which group you are assigned to, every eligible participant will ultimately receive the exact same 12-week professional visual training. This "delayed treatment" design is highly ethical. It ensures everyone gets treated while allowing us to compare the two groups transitionally during the first 12 weeks, thereby ruling out other factors like "getting used to the vision charts" or "gradually adjusting to new glasses".

Q2: How is the visual training performed? Is it difficult to do at home?

The training is fully home-based, meaning you do not need to visit the hospital constantly. However, it requires your dedication and, ideally, supervision from your family:

Training Tools: You will use the specialized RevitalVision perceptual learning software on a calibrated computer monitor.

Training Environment: The training should be done in a dark or standard low-light room. Your only main light source should be the computer screen, and you will sit exactly 1.5 meters away.

Glasses & Patching: You must wear your prescribed study glasses during training. If you have monocular (one-sided) amblyopia, you will need to patch your stronger eye (non-study eye), using only your weaker eye (amblyopia eye) to view the screen.

Frequency & Duration: You will train 4 times a week, for about 30 minutes per session, over a continuous span of 12 weeks. The software is adaptive: it automatically adjusts the difficulty of your next session based on your performance to keep you at your optimal training zone.

Q3: What do I need to do at the hospital during the study?

Your safety and visual health are our top priorities. We will provide meticulous, standardized eye examinations throughout the study:

Before the training begins, you will go through an 8- to 12-week "Refractive Stability Phase". During this time, we will perform cycloplegic refraction (dilation) and prescribe your glasses, checking your vision multiple times to ensure your baseline sight is completely stable.

During the study, you will only need to visit the clinic for follow-ups at Weeks 6 and 12 (the Delayed Group will also have visits at Weeks 18 and 24).

At these visits, our examiners (who do not know which group you are in to ensure objectivity) will measure your vision using standard ETDRS charts, evaluate your contrast sensitivity (using the computerized FrACT test), assess your stereoacuity (3D vision), and capture advanced 3D structural scans of your retina and choroid using Swept-Source OCT.

Q4: Is the training safe? What if my vision gets worse? The visual training is entirely physical and non-invasive, with an excellent safety record.

In very rare cases, some participants might experience mild, temporary eye strain, headaches, or slight discomfort when they first start training.

Double-Safety & Rescue Protocols: We have set strict "rescue criteria". If at any point during your observation or training, your vision drops significantly or if you experience persistent double vision, we will immediately initiate a professional assessment. If necessary, we will halt the training and provide standard clinical medical care.